. >> please welcome daniel lieberman. (cheers and applause) hey, good to see you, how are you, nice to see you again, daniel. all right. you have been on the show before, talked about barefoot run last time. >> yes. >> it is getting cold, i prefer to wear socks when it is cold. i'm just getting old and the older you get the more a crave warmth. >> stephen: that's one of the things that mod hirnl does that old humans didn't do, we get old, right. that's one of the advantages we have over them, we can just, in a fight we can just outlast them. >> that's true. >> what is interesting is the hunters gatherers, nasty miserable lives. >> stephen: they did. >> well, actually, the hunter gatherers if they survived childhood they had pretty high childhood mortality rates but if they survived they lived to their 60s, 70s and 80s and were extraordinarily healthy as far as we could tell. they had heart disease. they didn't have type ii diabetes. osteoporosis. we've got them all. >> stephen: we got that on them. >> yeah. >> stephen: th